Lock-up device

ABSTRACT

A lock-up device includes a clutch part and a damper part. The clutch part is disposed between a front cover and a turbine. The clutch part transmits or blocks torque. The damper part transmits torque from the clutch part to the turbine, and absorbs torsional vibration. The damper part includes an input member, an output member, a plurality of elastic members, and a support member. The input member is connected to the clutch part. The output member is rotatable relative to the input member and is connected to the turbine. The elastic members are accommodated in the input member, and elastically connect the input member and the output member in a rotational direction. The support member has a connecting part and a plurality of support parts. The connecting part is connected to the input member. The plurality of support parts support inner peripheral surfaces of the plurality of elastic members.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2020-095658, filed Jun. 1, 2020. The entire contents of that application are incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a lock-up device, particularly to a lock-up device for a torque converter transmitting a torque from a front cover to a transmission side member through a turbine.

BACKGROUND ART

A lock-up device for a torque converter generally has a damper part to absorb and reduce torsional vibration. A dumper part has an input side plate and an output side plate that can rotate relative to each other, and a plurality of torsion springs as elastic members provided between the two plates. Torque is input to the input side plate from the clutch part. Further the output side plate is connected to the turbine of the torque converter.

In a damper part as described above, it is necessary to support the inner and outer circumferences of a torsion spring in order to hold the torsion spring and stabilize the operation. For example, in the lock-up device of Japan Laid-open Patent Application Publication No. 2016-156384, the outer peripheral part of the plate on the input side accommodating the torsion spring is bent to form the outer peripheral support part, and a part of the inner peripheral part is cut up to form the inner peripheral support part.

BRIEF SUMMARY

In the lock-up device of Japan Laid-open Patent Application Publication No. 2016-156384, since a part of the plate on the input side is cut up to support the inner peripheral part of the torsion spring, the inner peripheral part is not sufficiently supported. If a long cut-out part is formed in the circumferential direction in order to provide sufficient support on the inner peripheral side, the strength of the plate is reduced. Further, in the lock-up device of Japan Laid-open Patent Application Publication No. 2016-156384, for the same reason, the length of the part supporting the torsion spring in the circumferential direction cannot be increased, so that the torsion spring gets into the gap between the support parts, and one piece, resulting in problems such as hitting.

It is an object of the present invention to enable a lock-up device to sufficiently and stably support a torsion spring without reducing strength of a member that supports the torsion spring.

(1) A lock-up device according to the present invention is a lock-up device for a torque converter transmitting a torque from a front cover to a transmission-side member through a turbine of the torque converter. The lock-up device is comprised a clutch part and a damper part. The clutch part is disposed between the front cover and the turbine. The clutch part transmits or blocks torque. The damper part transmits torque from the clutch part to the turbine, and absorbs and damps torsional vibration. The damper part includes an input member, an output member, a plurality of elastic members, and a support part. The input member is connected to the clutch part. The output member is rotatable relative to the input member and is connected to the turbine. The elastic members are accommodated in the input member, and the elastic members elastically connects the input member and the output member in a rotational direction. The support member has a connecting part and a plurality of support parts. The connecting part is connected to the input member. The plurality of support parts can support inner peripheral surfaces of the plurality of elastic members.

In this lock-up device, a support member is provided separately from the input member for accommodating the elastic member, and the support member supports the inner peripheral surface of the elastic member. Therefore, it is not necessary to form a cut-up part or the like for supporting the elastic member in the input member accommodating the elastic member, and the strength of the input member does not decrease. Further, since the support member is a separate member, the circumferential length of the part that supports the elastic member can be increased. As a result, the elastic member can be supported more reliably, and the operation of the elastic member is stable.

(2) Preferably, the circumferential length of the support part of the support member is 30% or more of the circumferential length of the elastic member. In this case, the elastic member can be supported reliably and stably.

(3) Preferably, the support member further has an annular main body formed inside the support part in a radial direction.

In this case, since the support member has an annular part, the inner peripheral surface of the annular part of the support member can be brought into contact with another member for radial positioning (centering). Therefore, a configuration for special positioning is not required, and the configuration of the entire device is simplified.

(4) Preferably, the input member has an accommodating part with a C-shaped cross section in which the elastic member is accommodated.

(5) Preferably, the support member includes a regulating part and a stopper part. The regulating part is provided to sandwich the output member between the regulating part and a part of the input member in an axial direction. The stopper part is contactable with the output member. The stopper part prohibits the input member and the output member from rotating relative to each other by a predetermined angle or more.

In this case, the output member is sandwiched between a pair of input side members (input member and support member), and they are made relatively immovable in an axial direction. In this lock-up device, the support member and the output member are brought into contact with each other in a circumferential direction to form a stopper mechanism for regulating the twist angle. That is, since the input member and the output member are made relatively immovable in the axial direction and the stopper mechanism is formed by these members, it is possible to prevent the stopper mechanism from coming off.

(6) Preferably, the output member includes a disk part and a plurality of engaging parts. The disk part has its inner peripheral part connected to the turbine, and the disk part has its outer peripheral part facing the regulation part of the support member in an axial direction. The plurality of engaging parts is formed to extend radially outward from the disk part, and the plurality of engaging parts having its outer peripheral part engaging with the circumferential end part of the elastic member. The plurality of engaging parts has its inner peripheral part contactable the stopper part of the support member.

According to the present invention as described above, in a lock-up device, a torsion spring can be sufficiently and stably supported without lowering strength of a member that supports the torsion spring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a torque converter provided with a lock-up device according to an embodiment of the present invention.

FIG. 2 is a figure which extracts and shows the lock-up device of FIG. 1.

FIG. 3 is a perspective view of a damper part according to an embodiment of the present invention.

FIG. 4 is a front view of a damper part according to an embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 is a partial cross-partial view of a torque converter 1 having a lock-up device 4 according to an embodiment of the present invention. An engine (not illustrated) is provided on the left side of FIG. 1, and a transmission (not illustrated) is provided on the right side of the figure. The O-O illustrated in FIG. 1 is a rotation axis of the torque converter 1 and the lock-up device 4. Further, in the following, the direction away from the rotation axis is referred to as a “radial direction”, and the direction along the rotation axis is referred to as an “axial direction”.

[Entire Configuration of Torque Converter 1]

The torque converter 1 is a device for transmitting torque from a crankshaft (not illustrated) on the engine side to an input shaft of a transmission. As illustrated in FIG. 1, a torque converter 1 includes a front cover 2, a torque converter main body 3, and the lock-up device 4.

The front cover 2 is fixed to the member on the input side. The front cover 2 is a substantially disc-shaped member, and has a disc part 2 a and an outer peripheral tubular part 2 b formed on the outer peripheral part of the disc part 2 a so as to project toward the transmission side.

[Torque Converter Main Body 3]

The torque converter main body 3 has an impeller 10, a turbine 11, and a stator 12. The impeller 10 has an impeller shell 15 fixed to the outer peripheral tubular part 2 b of the front cover 2 by welding. The turbine 11 is provided in a fluid chamber so as to face the impeller 10. The turbine 11 has a turbine shell 16 that constitutes an outer shell. A turbine hub 17 is provided on the inner peripheral part of the turbine shell 16. The turbine hub 17 has a hub 17 a provided at the center and a flange 17 b extending radially outward from the outer circumference of the hub 17 a. The flange 17 b is fixed to the inner peripheral part of the turbine shell 16 by a rivet 18. Further, a spline hole 17 c with which an input shaft (not illustrated) of the transmission is engaged is formed in the inner peripheral part of the hub 17 a. The stator 12 is provided between the inner peripheral parts of the impeller 10 and the turbine 11 and rectifies the hydraulic fluid returning from the turbine 11 to the impeller 10. The stator 12 is supported by a fixed shaft via a one-way clutch 20. A first thrust bearing 21 and a second thrust bearing 22 are provided between the stator 12 and the impeller 10; and the stator 12 and the turbine hub 17, respectively.

[Lock-up Device 4]

As illustrated in FIGS. 1 and 2, the lock-up device 4 is provided in the space between the front cover 2 and the torque converter main body 3. The lock-up device 4 transmits torque from the front cover 2 to the member on the transmission side via the turbine 11 of the torque converter 1. The lock-up device 4 includes a clutch part 24, a clutch operating part 27 including a piston 25, and a damper part 28.

<Clutch Part 24>

As illustrated in FIGS. 1 and 2, the clutch part 24 is provided between the front cover 2 and the turbine 11. Clutch part 24 transmits or blocks torque.

The clutch part 24 is a multi-plate type clutch. The clutch part 24 has an inner peripheral drum 30, an outer peripheral drum 31, and a plurality of first clutch plates 32 and second clutch plates 33, respectively.

The inner peripheral drum 30 has a fixed part 30 a and an inner peripheral tubular part 30 b. The fixing part 30 a is formed of a disk in an annular shape, and is fixed to the side surface of the front cover 2 by welding. The inner peripheral tubular part 30 b is formed by bending the outer peripheral part of the fixed part 30 a toward the turbine 11. A plurality of grooves are formed in the inner peripheral tubular part 30 b at predetermined intervals in the circumferential direction.

The outer peripheral drum 31 has a connecting part 31 a and an outer peripheral tubular part 31 b. The connecting part 31 a is formed of a disk in an annular shape. The outer peripheral tubular part 31 b is formed by bending the inner peripheral part of the connecting part 31 a toward the front cover 2. The outer peripheral tubular part 31 b is provided so as to face the inner peripheral tubular part 30 b of the inner peripheral drum 30 in the radial direction. A plurality of grooves are formed in the outer peripheral tubular part 31 b at predetermined intervals in the circumferential direction.

The plurality of first clutch plates 32 and the second clutch plates 33 are formed in a disk shape and are provided alternately in the axial direction. A plurality of teeth are formed on the inner peripheral part of the first clutch plate 32, and are slidably engaged with the groove of the inner peripheral tubular part 30 b of the inner peripheral drum 30. Therefore, the first clutch plate 32 cannot rotate relative to the inner peripheral drum 30, and is movable in the axial direction. Further, the second clutch plate 33 has a friction material fixed on both sides. A plurality of teeth are formed on the outer peripheral part of the second clutch plate 33, and are slidably engaged with the groove of the outer peripheral tubular part 31 b of the outer peripheral drum 31. Therefore, the second clutch plate 33 cannot rotate relative to the outer peripheral drum 31, and is movable in the axial direction.

<Clutch Operating Part 27>

The clutch operating part 27 is a mechanism for turning the clutch part 24 on (lock-up on state, that is, power transmission state) or off (lock-up off state, that is, power transmission release state), and includes a piston 25, a sleeve 35, and an oil chamber plate 36.

—Piston 25—

The piston 25 is formed in an annular shape and is provided on the transmission side of the front cover 2. The piston 25 is supported by the sleeve 35 so as to be movable in the axial direction.

The piston 25 has a disk part 25 a, an inner peripheral tubular part 25 b, and an outer peripheral tubular part 25 c. The outer peripheral part of the disk part 25 a bulges toward the front cover 2 side, and can press the first clutch plate 32 of the clutch part. The inner peripheral tubular part 25 b is formed so as to project from the inner peripheral end part of the disc part 25 a toward the front cover 2. The outer peripheral tubular part 25 c is formed so as to project from the outer peripheral end part of the disk part 25 a toward the turbine 11.

—Sleeve 35—

The sleeve 35 is a member extending in the axial direction and has a space in the center. The engine side of the sleeve 35 is inserted into the inner peripheral opening Q of the front cover 2 and fixed to the front cover 2 by welding. Further, the sleeve 35 has a piston support part 35 a, a first butt part 35 b, and a first engaging part 35 c on the turbine 11 side of the front cover 2.

The piston support part 35 a supports the inner peripheral surface of the piston 25 so as to be movable in the axial direction on the outer peripheral surface. The first butt part 35 b is formed in an annular shape on the outer peripheral surface of the piston support part 35 a on the turbine 11 side. The first engaging part 35 c is formed on the first butt part 35 b on the piston support part 35 a side adjacent to the first butt part 35 b. The first engaging part 35 c is annular and has a smaller diameter than the first butt part 35 b. That is, a step is formed between the first butt part 35 b and the first engaging part 35 c.

—Oil Chamber Plate 36—

The oil chamber plate 36 has a disk shape. The oil chamber plate 36 is provided between the piston 25 and the turbine 11. The oil chamber plate 36 forms an oil chamber C, to which a hydraulic fluid is supplied, between itself and the piston 25. A seal member 38 is provided on the outer peripheral surface of the piston support part 35 a, and the space between the piston support part 35 a and the inner peripheral tubular part 25 b of the piston 25 is sealed. Further, a sealing member 39 is provided on the outer peripheral surface of the oil chamber plate 36, and the space between the oil chamber plate 36 and the outer peripheral tubular part 25 c of the piston 25 is sealed. With these configurations, the oil chamber C is sealed.

Here, the disk part 25 a of the piston 25 is provided with a plurality of concave part 25 d concaved on the front cover 2 side. Further, the oil chamber plate 36 is provided with a plurality of convex parts 36 a that are inserted into and engaged with the concave part 25 d of the piston 25. Therefore, the piston 25, the oil chamber plate 36, and the front cover 2 cannot rotate relative to each other, so they rotate integrally with each other.

The oil chamber plate 36 has a second butt part 36 b and a second engaging part 36 c on the inner peripheral surface. The second butt part 36 b is in contact with the first butt part 35 b of the sleeve 35 and is butt welded. The second engaging part 36 c is annular and is formed on the oil chamber side of the second butt part 36 b. The second engaging part 36 c has a smaller diameter than the second butt part 36 b.

In such a configuration, since the sleeve 35 and the oil chamber plate 36 are butt-welded, both members 35 and 36 can be connected with a lower amount of heat and also beads are reduced as compared with welding by other lap welding or the like.

Further, on the oil chamber side of each of the butt parts 35 b and 36 b, a first engaging part 35 c and a second engaging part 36 c having a diameter smaller than that of the butt parts 35 b and 36 b are provided, and these engaging parts 35 c and 36 c are engaged. Therefore, even if the oil pressure of the oil chamber C becomes high and the oil chamber plate 36 is pressed toward the turbine 11, the second engaging part 36 c of the oil chamber plate 36 is supported by the first engaging part 35 c of the sleeve 35, so the joint strength between the sleeve 35 and the oil chamber plate 36 can be maintained high.

—Oil Channel—

A first oil passage P1 and a second oil passage P2 are formed in the sleeve 35.

The first oil passage P1 connects the inner circumference of the sleeve 35 and the oil chamber C. The radial outer opening of the first oil passage P1 is formed between the outer peripheral surface of the piston support part 35 a and the first butt part 35 b in the axial direction. Here, an opening of the first oil passage P1 is provided between the piston support part 35 a and the first butt part 35 b in the axial direction. That is, the piston support part 35 a, which requires high precision on the outer peripheral surface, and the first butt part 35 b to be welded (that is, exposed to high heat) are axially separated from each other. Therefore, it is possible to prevent the outer peripheral surface (that is, the piston support surface) of the piston support part 35 a from being affected by heat and the accuracy from being lowered.

The second oil passage P2 connects the inner circumference of the sleeve 35 and the space between the front cover 2 and the piston 25.

<Damper Part 28>

The Damper part 28 is provided on the outer peripheral side part of the lock-up device 4. The damper part 28 transmits torque from the clutch part 24 to the turbine 11, and absorbs and dampens torsional vibration.

As illustrated in FIGS. 1 to 4, the damper part has a retaining plate 45 (an example of an input member) fixed to a connecting part 31 a of the outer drum 31, a plurality of torsion springs 46 (an example of an elastic member), a driven plate 47 (an example of an output member) and a support plate 50 (an example of a support member).

—Retaining Plate 45 (Input Member)—

The retaining plate 45 is formed in a disk shape. The retaining plate 45 is provided between the front cover 2 and the driven plate 47 in the axial direction. The retaining plate 45 is connected to the clutch part 24. The retaining plate 45 supports a plurality of torsion springs 46 in the axial direction and the radial direction, and is engaged with the plurality of torsion springs 46 in the rotational direction.

The retaining plate 45 has an input side connecting part 451, an accommodating part 452, and a facing part 453.

The input side connecting part 451 is a part on the inner peripheral side of the retaining plate 45. The input side connecting part 451 is fixed to the connecting part 31 a of the clutch part 24 by a rivet 19.

The plurality of accommodating parts 452 have a C-shaped cross section that bulges toward the front cover 2. The accommodating part 452 further extends from the outer peripheral side end of the input side connecting part 451 to the outer peripheral side. The plurality of accommodating parts 452 are provided side by side in the circumferential direction, and a torsion spring 46 is accommodated therein. In the present embodiment, the number of accommodating parts 452 is three.

The facing part 453 is formed so as to extend from the end part on the inner peripheral side of the input side connecting part 451 toward the turbine 11 side, and the tip thereof can come into contact with the driven plate 47.

—Driven Plate 47 (Output Member)—

The driven plate 47 has a substantially disk shape and is rotatable relative to retaining plate 45.

The driven plate 47 has a disk part 471, an output side support part 472, and a plurality of engaging parts 473.

The inner peripheral part of the disk part 471 is fixed to the outer peripheral part of the turbine shell 16 of the turbine 11 and the turbine hub 17 by the rivet 18.

The output side support part 472 is formed in a tubular shape having a predetermined width in the axial direction in the radial intermediate part of the disk part 471.

The plurality of engaging parts 473 are formed so as to extend outward in the radial direction from the outer peripheral end part of the disc part 471. The outer periphery of the engaging part 473 is bent toward the retaining plate 45. This bent part is engaged with the end face of the torsion spring 46.

—Torsion Spring 46 (Elastic Member)—

The plurality of torsion springs 46 are accommodated in the accommodating part 452 of the retaining plate 45. In this embodiment, the number of torsion springs 46 is three.

The torsion spring 46 elastically connects the retaining plate 45 and the driven plate 47 in the rotational direction.

The circumferential end of the torsion spring 46 engages the outer peripheral part of the engaging part 473 of the driven plate 47.

—Support Plate 50 (Support Member)—

The support plate 50 has a substantially disk shape, and has a plurality of connecting parts 51 (support parts), a regulating part 52 (annular part), and a plurality of stopper parts 53 (contact parts), and a main body part.

A plurality of connecting parts 51 are disposed between the retaining plate 45 and the driven plate 47 in the axial direction. Each connecting part 51 is connected to the retaining plate 45 by the rivet 19.

The regulating part 52 is formed in an annular shape and is provided between the driven plate 47 and the turbine 11. The regulating part 52 is provided to sandwich the driven plate 47 between it and a part of the retaining plate 45 in the axial direction. The regulating part 52 is axially faced to the facing part 453 of the retaining plate 45. Further, the inner peripheral end surface of the regulating part 52 is supported by the output side support part 472 of the driven plate 47. As a result, the support plate 50 is radially positioned by the driven plate 47.

The stopper part 53 is provided between the plurality of connecting parts 51 and the regulating part 52 so as to connect them. The circumferential length of the stopper part 53 is shorter than the circumferential length of the connecting part 51. More specifically, the stopper part 53 is formed so as to extend from the radially inner end part of the connecting part 51 toward the turbine 11 side in the axial direction. The regulating part 52 extends radially inward from the end part on the turbine 11 side in the axial direction of the stopper part 53. The stopper part 53 is a part where the support plate 50 and the driven plate 47 intersect in the axial direction.

The stopper part 53 can come into contact with the inner peripheral part (more specifically, the end face in the circumferential direction of the engaging part 473) of the engaging part 473 of the driven plate 47. The stopper part 53 prohibits the retaining plate 45 and the driven plate 47 from rotating relative to each other by a predetermined angle or more.

The support plate 50 further has a plurality of support parts 54. The support part 54 is provided on the outer peripheral part of the connecting part 51. The support part 54 is a part in which the outer peripheral part of the connecting part 51 is bent toward the turbine 11. The support part 54 supports the inner peripheral surface of the torsion spring 46. In the present embodiment, the number of support parts 54 is three.

The circumferential length of each of the plurality of support parts 54 is longer than the circumferential length of the stopper part 53, as described above. The circumferential length of each of the plurality of support parts 54 is 30% or more of the circumferential length of the elastic member.

The support plate 50 further has a main body. The main body is annular. The main body part is formed inside the support part 54 in the radial direction.

[Actions]

First, the operation of the torque converter main body 3 will be described. When the front cover 2 and the impeller 10 are rotating, the hydraulic fluid flows from the impeller 10 to the turbine 11, and further flows to the impeller 10 via the stator 12. As a result, torque is transmitted from the impeller 10 to the turbine 11 via hydraulic fluid. The torque transmitted to the turbine 11 is transmitted to the input shaft of the transmission via the turbine hub 17.

When the speed ratio of the torque converter 1 increases and the input shaft reaches a determined rotation speed, the hydraulic fluid is supplied to the oil chamber C via the first oil passage P1. Also hydraulic fluid in the space between the front cover 2 and the piston 25 is discharged through the second oil passage P2. As a result, the piston 25 moves to the front cover 2 side. As a result, the pressing part of the piston 25 presses the first clutch plate 32 and the second clutch plate 33 against the side surface of the front cover 2 to enter a lock-up state (clutch-on state).

In the clutch-on state as described above, the torque is transmitted from the front cover 2 to the torque converter main body 3 via the lock-up device 4. That is, the torque input to the front cover 2 is output to the turbine hub 17 via the clutch part 24 and the damper part 28. In this clutch-on state, the torque fluctuation is attenuated by damper part 28 of the lock-up device 4.

[Features]

When the lockup is turned off (clutch off state) from the lockup state, the oil chamber C is connected to the drain. As a result, the hydraulic fluid oil chamber C is discharged through the first oil passage P1. Then, the piston 25 moves to the turbine 11 side, and the pressure of the piston 25 on the first clutch plate 32 and the second clutch plate 33 is released. As a result, the clutch is off.

In this lock-up device 4, a support plate 50 is provided separately from the member to which the torsion spring 46 is attached, and the support plate 50 supports the inner peripheral surface of the torsion spring 46. Therefore, in the retaining plate 45, it is not necessary to form a cut-up part or the like on the member to which the torsion spring 46 is attached, and the strength of the member to which the torsion spring 46 is attached does not decrease. Further, since the support plate 50 is a separate member, the circumferential length of the part supporting the torsion spring 46 can be increased. As a result, the torsion spring 46 can be sufficiently and stably supported without lowering the strength of the member that supports the torsion spring 46.

In this lock-up device 4, the driven plate 47 is sandwiched between a pair of input side members (retaining plate 45 and support plate 50), so that they cannot move relative to each other in the axial direction. Further, in the lock-up device 4, the support plate 50 and the driven plate 47 are brought into contact with each other in the circumferential direction to form a stopper mechanism for regulating the twisting angle. That is, the stopper mechanism is composed of the support plate 50 and the driven plate 47, which cannot move relative to each other in the axial direction. Therefore, the problem in the conventional stopper mechanism, that is, the disengagement between the claw and the engagement hole (disengagement of the stopper mechanism) is eliminated.

Other Preferred Embodiments

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

(a) In the above embodiment, the inner peripheral part of the torsion spring 46 is supported by the support plate 50 having a stopper or the like, but the torsion spring 46 can be supported by a member having only the support part 54, which is different from the support plate 50.

(b) The configuration of the support part 54 of the support plate 50 is not limited to the above-described embodiment in terms of number. For example, one torsion spring 46 can be supported by a plurality of divided support parts 54.

(c) The configuration of the clutch part 24 and the damper part 28 is not limited to the above embodiment. For example, the present invention can be applied in the same way to a single plate type clutch part 24. Further, the present invention can be similarly applied to the lock-up device 4 in which the damper part 28 is not provided.

REFERENCE SIGNS LIST

-   1 Torque converter -   2 Front cover -   4 Lock-up device -   24 Clutch part -   28 Damper part -   45 Retaining plate (example of input member) -   46 Torsion spring (an example of elastic member) -   47 Driven plate (example of output member) -   50 Support plate (example of support member) -   51 Connecting part -   52 Regulating part -   53 Stopper part -   54 Support part -   452 Accommodating part 

What is claimed is:
 1. A lock-up device for a torque converter configured to transmit a torque from a front cover to a transmission-side member through a turbine of the torque converter, the lock-up device comprising: a clutch part disposed between the front cover and the turbine, the clutch part configured to transmit or block the torque; and a damper part configured to transmit the torque from the clutch part to the turbine, the damper part configured to absorb and damp torsional vibration, the damper part including an input member connected to the clutch part, an output member rotatable relative to the input member, the output member connected to the turbine, a plurality of elastic members accommodated in the input member, the plurality of elastic members configured to elastically connect the input member and the output member in a rotational direction, and a support member, the support member having a connecting part connected to the input member, a plurality of support parts configured to support radially inner surfaces of the plurality of elastic members, and a stopper part configured to contact the output member, the stopper part further configured to prohibit the input member and the output member from rotating relative to each other by a predetermined angle, the stopper part being disposed radially inside of the connecting part.
 2. The lock-up device for a torque converter according to claim 1, wherein a circumferential length of each of the plurality of support parts of the support member is 30% or more of a circumferential length of each of the plurality of elastic members.
 3. The lock-up device for a torque converter according to claim 2, wherein the support member further has an annular main body formed inside the plurality of support parts in a radial direction.
 4. The lock-up device for a torque converter according to claim 1, wherein the input member has an accommodating part with a C-shaped cross section in which the plurality of elastic members is accommodated.
 5. The lock-up device for a torque converter according to claim 1, wherein the support member further has a regulating part provided such that the output member is interposed between the regulating part and a part of the input member in an axial direction.
 6. The lock-up device for a torque converter according to claim 5, wherein the output member includes a disk part having an inner peripheral part connected to the turbine, and an outer peripheral part facing the regulating part of the support member in the axial direction, and a plurality of engaging parts formed to extend radially outward from the disk part, each of the plurality of engaging parts having an outer peripheral part engaging with a circumferential end part of each of the plurality of elastic members, each of the plurality of engaging parts having an inner peripheral part configured to contact the stopper part of the support member. 